Exhibit 32(b)

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Cliffs Natural Resources Inc. (the “Company”) on Form 10-Q for the period ended September 30, 2010 as filed with the Securities and Exchange Commission on the date hereof (the “Form 10-Q”), I, Laurie Brlas, Executive Vice President, Finance and Administration and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to such officer’s knowledge:

 

  (1)

The Form 10-Q fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or 78o(d)); and

 

  (2)

The information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company as of the dates and for the periods expressed in the Form 10-Q.

 

Date:

 

October 29, 2010

/s/ Laurie Brlas

     Laurie Brlas

     Executive Vice President, Finance and

     Administration and Chief Financial Officer